Of course you are. But why not please keep Python 2.7 and Plone 4.3.X so that we can all be happy? We are not all experienced developers. EOL of Python 2.7 is not good for the business. Wonder if people are moving away from Plone because of this. Gone ask the Python Community to please rethink the EOL of Python 2.7. It is killing.
The EOL of Python 2.7 is incomprehensible. It even hurts. And there is no backward compatibility.
Well, all said. if @juron want to make 4.3 work on Tauton and if there are volunteers to help, nobody will stop them. It is both free software. But most in the Plone community I know and as @zopyx said are happy to go on with Python 3. No need to discuss the motivation of individuals here. There wont be a consensus.